Workers are threatening to down tools in the coming weeks as anger grows over the lack of progress in talks between trade unions and company management.

The drivers insist their pay has been "stagnant" in recent years and is now significantly below that of other drivers across the public transport sector.

Workers have been meeting in private in recent weeks over the prospect of holding work stoppages in the latter half of the year.

Ballot

The prospect of strike action by more than 200 Luas workers comes as the country's train drivers prepare to ballot on industrial action in a dispute over pay and conditions at the semi-state company Irish Rail.

Both sets of workers share similar grievances with their respective managements and are seeking pay increases as well as improvements in safety conditions.

The clear sense of discontent among the transport workers will prove deeply concerning for Transport Minister Paschal Donohoe, who has faced a number of looming disputes in his short time at the Department of Transport.

In relation to the Luas dispute, unions and management are scheduled to hold talks on September 29 at the Labour Court.

However, well-placed sources last night warned that strike action appears highly likely given the level of anger being vented by Luas drivers.

"Workers appear to have made their minds up and are deeply sceptical of any deal being brokered at the Labour Court," said a source involved in the negotiations.

"There's no doubt morale is very low and that we are moving closer to downing tools."

Siptu organiser Owen Reidy said all options would be considered following the outcome of the Labour Court process.

"We are very much looking forward to the Labour Court hearing, where we will put forward our claim for a pay increase. If the outcome meets our members' aspirations, then well and good. If it falls short, then all other options will be looked at," he said.

In a statement, the firm said: "Transdev Luas operator and SIPTU are in ongoing discussions regarding terms and conditions.

"The next stage is the Labour Court on September 29. Transdev is committed to the process and has engaged fully at all times with the drivers."